Treatment of furs and skins



Patented Apr. 11, 1939 PATENT, OFFICE TREATMENT OF FURS AND SKINS Wolf Kritchevsky, Chicago, Ill., assignor to Ninol, Inc., Chicago, Ill., a corporation of Illinois No Drawing. Application October 2, 1936, Serial No. 103,670

26 Claims.

My invention relates to the treatment of fur skins and more particularly is concerned with processing sheep skins or lamb skins in order to improve the luster thereof and to render them resistant to curling and spotting by reason of contact with moisture. Wherever the term skin is used herein, it is intended to cover the: skin together with the fur thereon. Thus, where reference is made to sheepskin, it will be under-' stood to mean the skin of the sheep together with the wool thereon.

become spotted as a result of contact those of sheep and lambs, to render them free or substantially free of the tendency to curl or with moisture or the like.

Another object of my invention is to produce dyed pelts or furs, particularly those of sheep and lambs, in imitation of more expensive furs but free from the defects which formerly characterized such articles, particularly from the standpoint of theefiect of moisture thereon.

Afurth'er object is to improve the lustering processesof the prior art and toproduce dyed pelts or furs, particularly those of sheep and lambs, having a superior lustrous appearance.

Still another object of my invention is to produce a. dyed'fur from sheep or lamb pelts in imitation of natural beaver having an improved luster and a superior resistance to curling and spotting over similar articles heretofore pre-' pared.

Other objects, not specifically set out above, will become apparent hereinafter in connection with a detailed description of the invention.

In general, my process comprises degreasing shearlings or the like after they have been sub-1 jected, upon removal from the animal, to the conventional preliminary steps of soaking, washing, tanning, drying, mordanting and dyeing. In some cases, the degreasing may precede the dyeing operation. After the degreasing opera- (Cl. 149--2s) tion, the resulting dyed and degreased shearling is impregnated with iodine, then dried, then treated with an oleaginous lustering material, following which the resulting shearling is "electrified, milled in dry sawdust, combed and is then ready for shearing.

In order to enable those skilled in the art to understand fully the details of my process, I shall now describe a specific embodiment of my invention by the practice of which I have obtained exceedingly satisfactory results. Certain permissible variations in the steps will be pointed out and others will be apparent to those skilled in the art, it being, of course, understood that the following detailed description is to be taken as illustrative as distinguished from precisely definitive of the entire invention.

As mentioned above, assuming the treatment of shearlings, the shearling is dyed to simulate any desired natural fur, for example, beaver, in accordance with methods well known in the art and forming no part of the present invention. It will be understood, of course, and as indicated above, that the dyeing is preceded by softening, washing, tanning and drying steps, all of which are likewise conventional, and require no description.

The dyed shearling, which has an area of about eight square feet, is preferably degreased by treatment with naphtha or Stoddard's solvent or any other suitable organic solvent in which the oleaginous or greasy material present on the shearling is soluble. Sometimes, it is advisable to subject the dyed shearling to two or more treatments with the degreasing solvent. The shearling or sheep-skin is then dried at a relatively low temperature, preferably in air, to remove the solvent and it is then subjected for a few hours, in most cases about three hours, at about 90 F. to a solution containing the following ingredients in the following proportions:

Water liters- 19 Common salt grams 900 Potassium iodide do 150 Iodine 90.

the solution, is wrung out and is then allowed to dry relatively slowly in air. Preferably the drying temperature should not exceed about degrees F. or else the leather becomes stifi. After drying, the skin is subjected to a lustering treatment. To this end. a solution of about 75 cc. of Perilla oil dissolved in 75 cc. of Stoddards solvent is brushed on the hairs, about 200 cc; of said solution being employed per eight square foot skin. The skin is then alternately ironed and combed or electriiied" at about 170 degrees F. and is thenmilled in dry sawdust to remove excess oil from the skin. For obtaining the most satisfactory results, it is sometimes advisable to subject the skin, after the first electrifying" and dry sawdust milling operations,

to a second oil brushing treatment followed by solution in an organic solvent.

another "electrifying" and dry sawdust milling treatment. This second treatment is, however, by no means essential and is employed only to insure the obtention of the very best results. The skin is then combed to remove the sawdust and it is then ready for shearing if desired.

The iodine solution employed for impregnating the skin contains approziimately 5 grams ofiodine per liter of solution. This gives excellent results. However, as the concentration of iodine decreases below this value, the results become progressively less satisfactory. The potassium iodide is employed to keep the iodine dissolved in the aqueous solution and the common salt serves to inhibit swelling or plumping of the leather.-

Sodium sulphate is another known salt which serves this same latter purpose. I have found that the employment of iodine-potassium iodide aqueous solutions in general gives superior results over the use of alcohol, carbon disulphide, carbon tetrachloride, or other organic solvent solutions of iodine although the latter give satisfactory results. It will also .be apparent that I can employ solutions which will liberate free iodine so that the element iodine can be absorbed by the skin. While I have stated that the temperature of the iodine bath is approximately degrees F., this is subject to some variation being dependent, among other things, upon the precise mode of tanning to which the skin was previously subjected. In general, a temperature of about degrees F. should not be exceeded in this step of the process in order to insure obtaining the best results.

Surprisingly enough, the skin absorbs as high as about I I grams of iodine per square foot of skin and, so far as my present knowledge is concerned, the best results are obtained in direct ratio to the amount of iodine absorbed by the skin. In general, with an iodine absorption of from 7 to 11 grams per square foot of skin, satisfactory results are obtained. I am led to believe at present that the iodine is absorbed by the unsaturated bonds present in the amino acids present in the hair of the skin thereby making said hair coarser and non-curling.

I have described hereinabove the utilization of Perilla oil in the lustering procedure following the impregnation of the skin with iodine. This oil is a drying oil with a high iodine value and I have found said oil to be eminently suitable for my purposes. AlthoughI have disclosed the utilization of the Perilla oil dissolved in an organic solvent, it is by no means necessary that a solvent be employed, it being feasible to brush the oil itself on the hairs. However, in general, it is easier to handle and brush on the oil when in Other known drying oils such as linseed oil and tung oil and semi-drying oils such as soya bean oil may also result of which the unsaturated bonds or linkages present in the oil absorb the iodine, analosoils to the action which takes place in making iodine number determinations of oils and the like.

i It is this mechanism which leads me to account for the better functioning of the unsaturated oils in the lustering process. However, I desire to make it clear that the lustering eifect of all of the lustering oils which I have employed is definitely improved by reason of the previousimpregnation of the skin with iodine. Likewise, I have found that the use alone of the drying oils and other oleaginous materials as lustering agents will not, to any noticeable extent, inhibit the tendency of the fur to become spotted upon contact with water. When, however, the lustering treatment is preceded by the described iodine impregnation step, the tendency to spot is practically completely eliminated.

Other precautions to be observed, if the best results are to be obtained, are as follows: The lustering oil should be applied directly after the iodine bath. That is, the skins should not be milled in sawdust before the application of the lustering oil. Care should also be taken that the sawdust employed in the operation of milling subsequent to the ironing or "electrifying treatment is dry. Otherwise, the luster obtained will not be completely satisfactory. As a general proposition, also, it is advisable to degrease the dyed skins in the manner described prior to' impregnating them with iodine. Ordinarily, the preliminary washing treatments and the like do not remove as much of the grease and oily material as is conducive to obtaining the best results.

I have stated hereinabove that organic solvent solutions of iodine may be employed although the results are not ordinarily quite so satisfactory as in the case of utilizing iodine-potassium iodide aqueous solutions. As illustrative of such practice, I subject a piece of the dyed degreased skin having an area of about one-half square foot to a solution of 10 grams of iodine in 750 cc. denatured ethyl alcohol. After drying as described previously, the sample is dipped in a solution of 75 cc. of tung oil in 7.50 cc. of naphtha. The skin is then electrified.

As a result of the practice of my invention, the

treated skins take on an enhanced utility which enables their usage in ways heretofore limited because of the above defects. Thus, for example, where, because of lack of resistance to moisture, dyed sheepskins could not fully satisfactorily be used in coats except as linings and trimmings, my process makes it possible to increase their use in the making of coats and the like in the same way that natural furs are used.

It must not be inferred that my process is applicable only to the treatment of the skins of sheep and lambs. Natural furs such as beaver and damp weather are susceptible to treatment in accordance with my process with the obtention of utility of my invention lies in connection with the treatment of sheep's and lambs skins.

, It will, of course, be apparent that by varyingthe dyeing technique and byemploying different dyes, the sheepskin or the like canv be made to simulate other more expensive skins such as fox, seal and the furs of longhaired animals.

While I have described my invention in considerable detail, it will be appreciated that certain changes may be made without departing from the spirit of my invention. a

What I claim as new and desire to obtain by .Letters Patent of the United States is:

l. The process of treating furs to improve their luster and to decrease the tendency of the hair or wool thereon to curl and become spotted due to the presence of moisture which includes the steps of impregnating said ,furs with iodine and then subjecting the resulting iodine-impregnated furs to a lustering operation to impart a luster thereto.

2. The process of treating dyed sheepskins to improve their luster and to decrease the tendency of the wool thereon to curl and become spotted due to the presence of moisture which includes the steps of strongly impregnating said skins with iodine and then subjecting said. impregnated skins to treatment with an oleaginous material to impart a luster thereto.

3. The process of claim 2 wherein the oleaginous material is amaterial of the group consisting of drying and semi-drying oils.

4. The process of claim 2 including degreasing the dyed sheepskins with an organic solvent prior to the iodine-impregnation step.

5. The process of claim 2 wherein the iodineimpregnation step is effected by contacting the dyed sheepskin with an aqueous-containing solution of iodine.

6. The process of treating dyedsheep skins to improve their luster and to decrease the tendency of the wool thereon to curl and become spotted due to the presence of moisture which includes the steps of degreasing said skins by means of an organic solvent, contacting said degreased skins with an aqueous solution containing not substantially less than 5 grams of free iodine per liter, drying the treated skin, and then subjecting the sameto treatment with an oleaginous material to impart a luster thereto.

7. The process of claim 6 wherein the oleaginous material is a member of the group consisting of drying and semi-drying oils.

8. The process of treating furs to improve their luster and to decrease the tendency of the wool or hair thereon to curl and become spotted due to the presence of moisture which includes the steps of strongly impregnating the furs with iodine, and subsequently subjecting the furs to an oleaginous treatment to impart a luster thereto.

9. The process of treating dyed sheepskins to improve their luster and to decrease the tendency of the wool thereon to curl and become spotted due to the presence of moisture which includes the steps of degreasing the dyed sheepskins by.

the skins at an elevated temperature to impart a luster thereto.

10; The process of claim 9 wherein the aqueous solution of iodine contains an agent to inhibit swelling of the leather on the skins.

11. The process of claim 9 wherein the skins are made to absorb between about '7 and 11 grams of iodine per square foot of skin.

12. The process of claim 9 wherein the lustering oil is applied in the form of an organic, solventsolution of said oil.

13. The process of claim 9 wherein the lustering oil is Perilla oil.

14. The process of treating dyed sheepskins to improve their luster and to decrease the tendency of the wool thereon to curl and become spotted due to the presence of moisturewhich includes the steps of degreasing the dyed sheepskins by means of an organic solvent, drying the degreased skins, contacting the dried degreased skins with an aqueous solution containing potassium iodide, iodine, and an agent which inhibits the swelling of the leather on the skins, said solution containing not susbtantially less than about 5 grams of free iodine per liter whereby the skins absorb between about 7 and 11 grams of iodine per square foot of skin, removing excess solution from said skins and then drying the latter, brushing an organic solvent solution of Perilla oil on the wool, electrifying the skins at an elevated temperature to impart a luster thereto, and then milling the skins in dry sawdust to remove excess oil therefrom.

15. A fur relatively strongly impregnated with iodine and coated with an oleaginous material, said furhaving a good luster and the hair or wool of which is substantially free from the tendency to curl or become spotted by contact of moisture therewith.

16. A dyed sheepskin relatively strongly impregnated with iodine and coated with an oil of the group consisting of drying and semi-drying oils, said skin having a good luster and the wool of which is substantially free from the tendency to curl or become spotted by contact of moisture therewith.

17. The article defined in claim 16 wherein the oil is Perilla oil.

18. The article defined in claim 16 wherein approximately 7 to 11 grams of iodine, is present for each square foot of skin.

19. A dyed sheepskin having the appearance of natural beaver fur, said skin being relatively strongly impregnated with iodine and the wool of which is coated with an oleaginous material. said skin having a good luster and the wool of which is substantially free from. the tendency to curl or become spotted by contact of moisture therewith.

20. The article defined in claim 19 wherein approximately 7 to 11 grams of iodine is present for 'each square foot of skin, and wherein the oleaginous material is a member of the group consisting of drying and semi-drying oils.

21. As a new article of manufacture, a fur relatively strongly impregnated with iodine, the hair of said fur being substantially free from the tendency to curl upon contact with moisture.

2 The process of treating furs, particularly sheepskin, the hair of which furs has a natural tendency to curl upon contact with moisture, which includes the step of impregnating the furs with a relatively strong solution of iodine to substantially inhibit the tendency of the hair of the fur to curl or spot.

natural tendency oi the hair on said skins to curl up;5n cgnislct wgltlh moisture.

eep n relatively strongly impregnated withiodine, the hair oi said skin being substantially tree from the tendency to curl upon contact with moisture.

2 A dyed iur relatively strongly-impregnated with iodine, the hair of said iur being substantially tree from the tendency to curl upon contact with moisture.

WOLI' KRI'ICKEVBKY. 

